1. Field of the Invention
This invention relates to cyclodextrin derivatives and a process for measuring a contamination degree of water by using the same, and more particularly to a process for measuring a contamination degree of water by using the cyclodextrin derivatives according to the invention to measure a contamination degree in a purifying cartridge used in a water purifier thereby to detect an exchanging time of the purifying cartridge.
2. Description of Related Art
As a method of purifying drinking water, there have been used various water purifiers. However, it is difficult to detect an exchanging time of a purifying cartridge used in such a purifier, so that it is the present condition that the lapse of constant time is the exchanging time instead of measuring the contamination degree of the purifying cartridge.
The inventors have made various studies with respect to the use of the fluorescent cyclodextrin derivative as a detecting substance (sensor) for measuring a contamination degree of water existing in our immediate surroundings from the old time, but satisfactory compounds could not be obtained.
A certain cyclodextrin derivative is selected from the cyclodextrin derivatives as examined above and dissolved in water and added with a given organic compound, which is exposed to a ultraviolet ray to measure a fluorescent intensity developed. As a result, it has been confirmed that naphthol-modified cyclodextrin tends to indicate a remarkable change in the fluorescence intensity as shown by graph showing a relation between an amount of the organic compound added and the fluorescence intensity. Now, the inventors have synthesized various cyclodextrin derivatives by changing a position of hydroxy group on a naphthol ring and made further studies in order to satisfy the above demand.
Under the above circumstance, the inventors have examined various cyclodextrin derivatives having naphthol ring and found out that novel cyclodextrin derivatives as mentioned later are excellent as a fluorescent substance.
According to a first aspect of the invention, there is the provision of a cyclodextrin derivative being an X-hydroxynaphthalene-Y-amidated cyclodextrin formed by subjecting a starting cyclodextrin to an addition reaction with A-hydroxyl-B-carboxyl naphthalane.
According to a second aspect of the invention, there is the provision of a process for measuring a contamination degree of water which comprises adding the cyclodextrin derivative defined in the first aspect of the invention as a host compound to water dissolving a slight amount of a contaminant therein and then irradiating a ultraviolet ray thereto to develop fluorescence at a given wavelength.